1. Field of the Invention
The present invention relates to methods of fabricating nonvolatile memory devices. More particularly, the present invention relates to a methods of fabricating nonvolatile memory devices having improved reliability.
2. Description of the Related Art
Nonvolatile memory devices are devices that are able to electrically erase data, program data and store data even in the absence of power. Nonvolatile memory devices are being used more often in a wide variety of fields.
Nonvolatile memory devices may be classified as stack gate types and split gate types. Split gate types of nonvolatile memory devices generally include a floating gate and a control gate, which are separated from each other.
When forming a common source of a split gate type nonvolatile memory device, ions may be injected in high doses and energy levels in order to partially overlap the common source with the floating gate. During formation of the common source ions, may be injected while the floating gate and tunnel oxide film are partially exposed. Thus, the floating gate and the tunnel oxide film may be damaged, attributable to the excess doses and energy levels, resulting in reduced reliability of the nonvolatile memory device.